1. Field of the Invention
The present invention relates to a coating composition of a photocatalyst.
2. Description of Background Art
A photocatalyst is a catalyst which exhibits a catalytic activity when it is irradiated with light, and it is often used in the form of a coating composition comprising the photocatalyst and a binder and coated on a substrate to form a coating film containing the photocatalyst (see WO 98/15600, JP-A-2003-105262, JP-A-9-328336, JP-A-2004-59686, WO01/023483 and JP-A-11-209691).
However, a coating film formed from a conventional coating composition of a photocatalyst may not always have sufficient adhesion strength to a substrate. Therefore, an amount of a binder in relation to an amount of the photocatalyst should be increased. When the amount of the binder is increased, the photocatalyst may not sufficiently exhibit its activity.